Dryer for processed photographic paper and method of transporting paper therethrough

ABSTRACT

THE INVENTION DISCLOSED HEREIN RELATES TO A DRYER FOR PROCESSED PHOTOGRAPHIC PAPER AND PARTICULARLY TO A DRYER HAVING A WARM AIR CIRCULATING SYSTEM WHICH INCLUDES A HOLLOW UPSTANDING VACUUM STACK OVER WHICH THE PAPER TO BE DRIED TRAVELS (UP ONE SIDE AND DOWN THE OTHER) AND INTO WHICH THE DRYING AIR IS DRAWN BY THE INTAKE OF A CIRCULATING BLOWER, THE STACK BEING PROVIDED WITH A PLURALITY OF VENT OPENINGS AND PAPER ENGAGING SPACER AND RETARDING ELEMENTS TO KEEP THE PAPER SPACED FROM SAID VENTS, THE VENT OPENINGS BEING DESIGNED SO THAT THE VELOCITY OF THE AIR TRAVELING INTO THE STACK IS GREATER THAN THE VELOCITY OF THE MOVING AIR OUTSIDE THE STACK TO HOLD THE PAPER AGAINST THE SPACER ELEMENTS AND FRICTIONALLY RETARD THE FREE END OF THE WEB AT THE END OF EACH ROLL OF PAPER TO POSITIVELY PREVENT SAID FREE END FROM FALLING AWAY FROM THE STACK AS IT DESCENDS ON THE DOWN SIDE THEREOF.

Oct. 5, 1971 c RElD 3,609,815

DRYER FOR PROCESSED PHOTOGRAPHIG PAPER AND METHOD OF TRANSPORTING PAPERTHERETHROUGH Filed June 6, 1969 [WWW M A lrroklwv United States PatentGhee DRYER FOR PROCESSED PHOTOGRAPHIC PAPER AND METHOD OF TRANSPORTINGPAPER THERETHROUGH Norman C. Reid, Minneapolis, Minn, assignor to PakoCorporation, Minneapolis, Minn. Filed June 6, 1969, Ser. No. 831,017Int. Cl. F26!) 13/06 US. Cl. 34-159 4 Claims ABSTRACT OF THE DISCLOSUREThe invention disclosed herein relates to a dryer for processedphotographic paper and particularly to a dryer having a warm aircirculating system which includes a hollow upstanding vacuum stack overwhich the paper to be dried travels (up one side and down the other) andinto which the drying air is drawn by the intake of a circulatingblower, the stack being provided with a plurality of vent openings andpaper engaging spacer and retarding elements to keep the paper spacedfrom said vents, the vent openings being designed so that the velocityof the air traveling into the stack is greater than the velocity of themoving air outside the stack to hold the paper against the spacerelements and frictionally retard the free end of the web at the end ofeach roll of paper to positively prevent said free end from falling awayfrom the stack as it descends on the down side thereof.

It is an object of the present invention to provide a dryer forprocessed photographic paper which is specifically designed to maintainfeeding and driving control over the entire length of the paper webincluding the free end at the end of each roll thereof.

It is another object to provide a vacuum stack within a dryer forprocessed photographic paper which is designed to hold the paper againstspacing and retarding elements by means of a vacuum effect produced bythe drying air as it is circulated through the vacuum stack into theintake of the circulating blower.

These and other objects and advantages of this invention will beapparent from the following description made in connection with theaccompanying drawing wherein like reference characters refer to similarparts throughout the several views, and in which:

FIG. 1 is a vertical sectional view of a dryer embodying my invention;and,

FIG. 2 is a fragmentary horizontal section taken substantially along theline 22 of FIG. 1.

A dryer is illustrated in the accompanying drawing which is adapted todry a web of photographic print paper 4 after the same is processedthrough the various processing solutions. The dryer includes a housing 5with a paper inlet opening 5a and discharge opening 5b. A stack unit 6is mounted inside the dryer housing 5 and is provided with a pluralityof horizontally spaced apart rows of vertically spaced intake vents eachhaving an outwardly extending louver 7. A transport belt 8 travels inthe unobstructed area between the horizontally spaced rows of louvers. Acirculation blower 9 is mounted in the bottom of the housing 5 with itsintake 9a in communication with the stack 6. The discharge from theblower passes over a heating element 10 and is circulated upwardlywithin the housing 5 in contact with the paper being dried. Each of thestack openings adjacent the louvers permits air to be drawn into thestack to provide the sole means for supplying the intake of the blower9. A pair of driven rollers 11 and 12 operating at the same speed arerespectively provided at the intake and discharge openings 5a and 5b.These rollers are meshed with the perforated transport belt 8 in amanner similar to that disclosed in 3,509,875 Patented Got. 5,, 1971 mycopending application filed of even date herewith and entitled Methodand Apparatus for Processing Photographic Prints. Idler rollers 13, 14and 15 guide the paper 4 and the belt 8 around the stack 6 asillustrated and a belt receiving groove is provided at the centerportion of the upper roller 14 to receive the belt and permit contactbetween the paper and said roller.

As the air passes into the stack through the restricted openings behindeach of the louvers 7 the velocity is increased from the velocity of theair being blown upwardly around the stack 6 within the housing 5. Thishigher velocity produced on the air passing through the louvers anddownwardly within the stack 6 reduces the pressure on the back side ofthe paper causing the paper to be attracted toward the stack and held inengagement with the outer edges of the louvers 7. This vacuum attractionagainst the edges of the louvers provides sufficient resistance to thepaper to maintain control of the free end of each paper roll beingprocessed as it descends on the down side of the stack and prevents thistrailing free end from falling away from the stack which could damagethe paper. A pair of vent openings 16 are provided at the top of thehousing 5 to permit a portion of the hot moisture-filled air to escape.This air is also released from the housing through the discharge opening5b.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportion of the parts withoutdeparting from the scope of the invention, which generally stated,consists in the matter set forth in the accompanying claims.

What is claimed is:

1. A dryer for separate strips of web material comprising:

a housing having a web inlet opening and a web discharging opening,

a hollow upstanding stack unit mounted within said housing and having aplurality of spaced apart vent openings, and a plurality of web-engagingportions,

means for guiding the web through a fastooned path within said housingand around said stack unit, and

means for drawing air into said stack unit through said vent openings toproduce a vacuum effect and hold said web against said web-engagingportions to prevent the trailing of each web strip from falling out ofsaid festooned path within said housing as it travels therethrough.

2. The structure set forth in claim 1 and said webengaging portionscomprising means extending outwardly from said stack unit between thesurface thereof and the web material for maintaining a spaced relationbetween the web and the adjacent stack surface to control the air flowtherebetween and into the vents.

3. The structure set forth in claim 2 wherein said spacing meanscomprises a plurality of web engaging and retarding louvers adjacent atleast certain of said vent openings.

4. The structure set forth in claim 1 wherein the guiding means iscomprised of a transport belt to which the leading ends of unsplicedwebs of material is secured, the belt constituting a continuousstructure drawn through the festooned path in said dryer from inletopening to discharge opening.

References Cited UNITED STATES PATENTS 2,439,722 4/1948 Dreisel 341592,597,999 5/1952 Knopp 34-159 X 2,780,878 2/1957 Sanborn et a1. 341592,920,399 1/1960 Fry 34-159 3,405,456 10/1968 Shepherd 34-155 EDWARD J.MICHAEL, Primary Examiner

